2. In a domestic combined heat and power (CHP) system natural gas is used as fuel in a free-piston Sterling engine. Rejected heat is used to warm the water of the central heating system. The Sterling engine free piston oscillates a set of magnets configured to produce radial flux inside the cylindrical coil of a utility connected linear single-phase synchronous alternator at 50 Hz. The amplitude of the oscillations is 50 mm. The coil has an average diameter of 150 mm. The radial gap magnetic flux density is 0.5 T. The coil's resistance is 0.25 2. The alternator's no-load emf was measured to be 255 V rms. a. b. C. Draw a cross-section of a possible configuration of the linear generator. Show flux lines and types of material used. Explain the rationale for the construction and choice of materials. Estimate the number of turns of the generator. [10 marks] [15 marks] Calculate the coil's wire diameter assuming the resistivity of hot copper is 2 ncm. [4 marks] d. If the generator supplies a current of 15 A rms, calculate the peak electromagnetic force on the permanent magnet translator. [4 marks]